The agency plans to argue that the company illegally penalizes customers that try to use rival payment processors.

The Department of Justice (DOJ) filed an antitrust lawsuit against Visa. The lawsuit alleges that the financial firm holds a monopoly over debit network markets allowing it to charge banks and markets with exorbitant fees that get passed onto consumers and keep rival companies like PayPal and Square from competing on their level.

The U.S. Department of Justice has filed an antitrust lawsuit against Visa, alleging that the debit card corporation uses its dominance in the industry to conduct an illegal monopoly practice for debit card payments that costs businesses and customers billions of dollars.